Descemet membrane endothelial keratoplasty in patients with prior glaucoma surgery

Objective: To present outcomes of Descemet membrane endothelial keratoplasty (DMEK) in eyes with prior trabeculectomy or a glaucoma drainage device (GDD). Methods: A retrospective case series, including patients that had previously undergone trabeculectomy and/or GDD implantation, who later underwent DMEK between 2013 and 2016 at Toronto Western Hospital and the Kensington Eye Institute. Outcome measures: best spectacle-corrected visual acuity (BSCVA), endothelial cell (EC) density, intraoperative and postoperative complications. Results: Twenty-seven eyes of 27 patients were included. All DMEK procedures were uneventful. Mean follow-up time was 14.6 ± 6.1 months. In eyes with no visually limiting comorbidities (n = 16), BSCVA improved from 1.34 ± 0.65 logMAR (Snellen equivalent ~20/440) preoperatively to 0.51 ± 0.24 logMAR (Snellen equivalent ~20/65) and 0.50 ± 0.33 logMAR (Snellen equivalent ~20/65) at 6 and 12 months, respectively (p < 0.001 for both). In eyes with visually limiting comorbidities (n = 11), BSCVA improved from 1.92 ± 0.72 logMAR (Snellen equivalent ~20/1665) preoperatively to 1.43 ± 0.83 logMAR (Snellen equivalent ~20/540) and 1.37 ± 0.99 logMAR (Snellen equivalent ~20/470) at 6 and 12 months, respectively (p = 0.008 and p = 0.037). Graft detachment rate was 24.1% and rebubble rate was 17.2%. Primary and secondary graft failure rates were 3.7% and 10.3%, respectively. Rejection rate was 17.2%. EC-loss rate at 6 months and 12 months was 36.7% and 50.5%, respectively. Conclusions: DMEK performed in eyes with previous trabeculectomy or a GDD is more challenging than conventional DMEK, but has good outcomes. Higher rates of graft rejection and secondary graft failure in this setting should be further evaluated in long-term studies.